Portable power-operated abrading machine



Oct. 6, 1953 w. G. MITCHELL PORTABLE POWER-OPERATED ABRADING MACHINE 2 Sheets-Sheet 1 Filed May 13, 1949 FIG. 3

INVENTOR. WALTER 6. MITCHELL- A TTORNEY Oct. 6, 1953 W. G. MITCH ELL PORTABLE POWER-OPERATED ABRADING MACHINE 2 Sheets-Sheet 2 Filed May 13, 1949 v mmvroa.

WALTER G. MITCH-ELL BY 4 9m, M M-I-W ATTORNEY Patented Oct. 6, 1953 PORTABLE POWER-OPERATED ABRADING MACHINE Walter G. Mitchell, Aurora, 111., assignor to Thor Power Tool Company,

tion of Delaware Aurora, 111., a corpora- Application May 13, 1949, Serial No. 93,127

7 Claims. (Cl. 51-170) This invention relates to improvements in portable, power operated, sanders and abrading machines for smoothing and/or finishing metal and/or non-metallic surfaces.

v The principal object and purpose-of my invention is to provide the machine with means whereby a suction fan may be readily and easily applied to the machine to serve as a unit for removing the sanding and/r abrading dust in the the fan unit.

The invention consists further in the features of construction and combination of parts hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is a side elevationview of a power operated, portable, sanding or abrading machine embodying the fan assembly of my invention;

Fig. 2 is a view on a larger scale of the rear end portion of the machine showing the gear train which drives the machine parts;

Fig. 3 is an end view of the assembly shown in Fig. 1 partly broken away to illustrate certain details of the construction to be hereinafter described;

Fig. 4 is a vertical sectional view taken on line 44 of Fig. 3;

Fig. 5 is a top plan view of the assembly shown in Fig. 4; and

Fig. 6 is a vertical sectional view taken on line 6-6 of Fig. 4 to show a detail of construction.

In the drawings, 1 indicates the supporting frame of a portable, power operated, sanding or abrading machine of the desired size and shape. The support I has a lateral wall 2 at one side of the machine to support a pair of revolvable drums or pulleys 3, 4 adjacent to the opposite ends of the machine as in devices of this character. Trained or looped about the drums 3, 4 is an endless, fiexible, belt 5 having an outer sanding or abrading surface 6. v The abrading material employed on the beltis of the kind intended for th work to be performed by the machineifi 25, one end of which is journalled in a. boss 26 The belt 5 is removable from the drums 3, 4 for changing or replacement as may be required in the use of the machine, the latter being made open on its side opposite to the wall '2.

The drum 3 which is adjacent to the front end of the machine is the idler drum, while the drum '4 which is adjacent to the rear end of the ma- ..chine is the driving drum, the latter being connected to and driven by the power motor 1 mounted on the frame I as indicated in Fig. 1. The motor 1 may be electrically operated, the "machine being equipped with an electric current supply cable (not shown) for the motor as .in devices of this character. A gear train is' indicated in Fig. 2 and has a "series of gear wheels 8, 9, l0 and II, the latter ,being keyed or otherwise fixed to the armature shaft [2 of the power motor I. The gear wheel ll is shown in the form of a pinion. The gear wheel 8 is keyed or fixed to the axis element I3 lot the driving drum 4.

The intermediate gear wheels 9 and ID are .shown in detail in Fig. 2, all of the gear wheels, that is, the gear train, being located within a protective case or housing l4 fixed to and car- "ried by the frame I adjacent to the rear end of the machine and on the same side as the jside wall 2. A plate l5 fits over and covers the front side of the gear box l4, screws or fasteners [6' being employed to releasably secure the cover I5, in place. The rear wall I! mounts the gear wheels 9 and Ill and. extends above the top wall l8 of the support I to reach the armature shaft l2 and the fan shaft, the latter to be presently described.

Fixed or otherwise secured to the motor I is a handle member l9 disposed at the rear end of the machine frame I. The handle [9 may 1 also be fixed to the support I, the handle mem- -ber IS in accordance with my invention being .spaced laterally from the gear box l4 where the latter extends above the frame wall [8. The handle member [9 may be of the D-type to be grasped by one hand of the operator manipulating the machine and contains the control switch for the tool motor 1.

The space above mentioned is shown in Figs. '3 and 5 and is marked 20. Located in the space '5 20 is rotary fan 21 of the suction type for re- 'moving' dust. Said fan 2| has an outer casing 22 providing an operative chamber for the radiallike fan vanes 23 as shown in Figs. 4 and 6.

The air inlet 24 for the fan is about the shaft 3 on the front wall 21 of the fan casing. This wall 2'! is held in place by screws or fasteners 28 adjacent to the outer periphery of the parts as shown in Figs. 4 and 6. 'Said cover wall 21 is fashioned with an air passage 29 joined at one 5 end with the intake 24 for the fan and at its lower end with a passage 32- in a casting or fixture 3| at the rear end of the machine and conforming generally to the curvature of the driving drum 4 and is cut-off at an angle as at:

33 to increase the passage for the dust thrown by the tangential action of the moving belt 5, the latter being rotated by the drums 3, 4 as welt understood in this art.

The outlet for the fan at at its periphery 1-5 and opens into a discharge spout 34 rising upwardly from the fan housing 22 and to which spout a dust collecting bag (not sho'wnl of the customary type as used in these dust collecting systems is releasably connected. The bag is supported in operative position above the machine frame I not in the way of the handle 19 by a wire attachment (not shown) applied to either the machine frame or to the spout 34.

The rear wall 35 of the fan housing 22 fits 25 flatwise against the gear case wall #1 as shown in Fig. 6. Here, it be noted that screws or fasteners 36, 31 secure the fan housing wall 35 to the gear box wall I'l. Two screws 36 are threaded into bosses 38 on the gear box casing, while two 30 ofthe screws 3! are threaded directly into the wall I! and are disposed below the lugs as indicated in- Fig. 2.

Between these fasteners 36, 3-1," the box wall [-1 is provided with a relatively large opening 39 35 aligned with the fan shaft 25 for the latter to extend into the gear box and locate the pinion 40 on said shaft for meshing with the adjacent ear wheel 9 as indicated in Fig. 2.

Hence, when the fan assembly is located in the 40 space 20 and mounted to the gear box M the fan 24 is connected with the motor I for operation thereby.

The machine frame or support I has a. bed

plate 4| to support the lower lap or run of the belt 5 when the machine is pressed against the surface or work to be treated.

At 42 is a fixture for mounting the axis member of the idler drum 3 for tightening and loosening the belt 5 and aligning the drumv with the driv- 5;

ing drum 4 as disclosed and claimed in the copending application of Melvin B.- Gentzel, Serial No. 13,776 filed March 9, 1948, now Patent No. 2,565,223, dated August 21, 1951.,

With the gear casing 14 provided as above described, thev fan 2| may be used with the machine as a unit when desired. The applying may be quickly and easily made and the machine given a dust collecting system. In this connection I might point out that the wall 3| carries a flexible or rubber-like strip 43 to bear against the work surface to deflect the dust particles into the conduit 30. I might also point out that a gasket 14 seals the joint between the casing 3i and the fixture 26 where meeting as'shown herein, A

tended.

The details of construction and arrangement of parts shown and described may be variously changed and modified without departing from the spirit and scope of my invention, except as pointed out in the annexed claims. $5

I claim as my invention:

1. In a portable power operated abrading machine of the character described, a support, an abrading element and a power motor for operating the same, both mounted on said support, a handle at one side of the support and extending rearwardly of said motor, a gear train directly connecting the motor to saidabrading element for operating the same, a gear case on the support enclosing the gear train, said gear case being laterally spaced from the handle and extending re'arwar'dly of said motor in parallel relation with said handle to provide a space therebetween, a suction: ran for removing dust from said machine mounted insaid space and having a housingdetachably secured to said gear case, the latter having an opening therein facing said fan, a shaft for the fan extending through said opening, and a gear pinion on the shaft within said gear case in mesh with one of the gear wheels of the gear train.

2. In a portable power operated abrading machine of the character described, a support, an abrading element and a power motor for operating the same, both mounted on said support, a handle at one side of said support, a gear train operatively connecting the motor to said abrading element-for operating the same, a gear case on the support enclosing said gear train, said gear case being laterally spaced from said handle to provide a space therebetween, a suction fan for removing dust from the machine mounted in said space and comprising a housing having an inner wall adjacent to said gear case in contact with and detachably secured thereto, a shaft for said fan having a. pinion extending into said gear case and operatively connected with one of the gear wheels of the gear train, and an outer wall for the fan housing opposite to said pinion and providinga bearing for the adjacent end of said shaft.

3. In a portable power operated abrading machine of the character described, a support, an abrading element. and a power motor for operat ing the same, both mounted on said support, a handle at one side of said support, a gear train operatively connecting the motor to said abrading element for operating the same, a gear case on the, support enclosing said gear train, said gear case being laterally spaced from said handle to provide a space therebetween, a suction fan for removing dust from said machine mounted in said space and having an outer housing detachably supported by said gear case, and the outer wall of the fan housing providin an intake for the fan and air flow passage leading thereto.

4. In a portable power operated abrading machine of the character described, an elongated supporting frame having abrading means operatively supported therein, a motor mounted above said frame adjacent the rear end thereof, an upright gear case secured at one side of said frame adjacent said rear end and projecting upwardly above said frame, the upper end of said gear case having a forwardly extending portion adjacent said motor and also having a portion extending rearwardly of said motor, gear means within said gear case directly connecting said motor with said abrading means, a removable fan housing disposed rearwardly of said motor and detachably secured in fiatwise relation against said gear casing at the rearwardly extending portion thereof, and a suction fan rotatably supported in said housing on a substantially horizontal axis and having a fan shaft extendin ing at said rearwardly extending portion of the gear case, a motor mounted above said frame and having a shaft extending into said gear case at said forwardly extending portion thereof, gear means within said gear case directly connecting the motor shaft with said abrading means, and a. removable fan housing detachably secured fiatwise against the inner wal1 of said gear case at said rearwardly extending portion of the latter and rearwardly of said motor, said fan housing having a suction fan rotatably supported therein on a substantially horizontal axis with the fan shaft extending through said opening in said inner wall of said gear case into operative engagement with said gear means for driving said fan.

6. In a portable power operated abrading machine of the character described, an elongated supporting frame having abrading means operatively supported therein, a motor mounted above said frame adjacent the rear end thereof, an upright gear case secured at one side of said frame adjacent said rear end and extending upwardly above said frame adjacent said motor, gear means within said gear case operatively connecting said motor with said abrading means, an operating handle extending rearwardly of said motor and disposed above said frame, said handle being spaced transversely from said gear case to provide a fan-receiving space therebetween, a suction fan and housing disposed in the space between said handle and said gear case with said housing being detachably secured to the inner face of said gear case and said fan being operatively connected to said gear means, and a suction chamber communicating with said fan hous- Mini 6 ing and extending downwardly and laterally below said handle into communication with said abrading means adjacent the rear of said supporting frame for removing dust during operation of the machine.

7. In a portable power operated abrading machine of the character described, an elongated supporting frame having abrading means operatively supported therein, a motor mounted above said frame adjacent the rear end thereof, an upright gear case secured at one side of said frame adjacent said rear end and extending upwardly above said frame adjacent said motor, gear means within said gear case operatively connecting said motor with said abrading means, a removable fan housing having an integral inner wall detachably secured to said gear case rearwardly of said motor, a suction fan in said fan housing having a shaft journaled in said inner wall and extending into said gear case and. operatively connected to said gear means, an outer wall detachably secured to said fan housing and providing a bearing for the opposite end of said shaft and an air intake for said fan, and a suction chamber secured to said supporting frame and communicating with said air intake and said abrading means for removing dust during operation of the machine.

WALTER G. MITCHELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,404,342 Clarke Jan. 24, 1922 1,732,594 Clarke Oct. 22, 1929 1,804,523 Wolfe et a1. May 12, 1931 1,945,425 Emmons Jan. 30, 1934 2,000,784 Myers May '7, 1935 2,069,502 Myers Feb. 2, 1937 2,106,535 Pattison et a1. Jan. 25, 1938 2,204,840 Wilkie June 18, 1940 FOREIGN PATENTS Number Country Date 253,535 Switzerland Nov. 16, 1948 

